1. Field of the Invention
The present invention relates to a non-isolated AC/DC converter with power factor correction, in particular, to a single stage circuit architecture without using any transformers, therefore, reducing the circuit volume, lowering costs, raising circuit conversion rates, and thus achieving the goals of power factor correction and increasing the lifespan of the transformer, moreover, through the waveform controller controlling the output waveform, the storage circuit can utilize a lower capacity capacitor to avoid using an electrolytic capacitor, thereby increasing the circuits lifespan.
2. Description of Related Art
Most traditional AC/DC converters require a rectifier circuit which converts the input AC power supply into DC power, and the output end of the rectifier circuit is in parallel with the direct current link output capacitor, and also serves as a circuit filter and for storing energy.
The size of the storage value of the Direct Current link output capacitor and the output ripple voltage becomes inverse, and the storage value of the capacitor also increases. This also means that within the input AC voltage cycle period, the time period that the input AC voltage is lower than the capacitor voltage also increases accordingly.
Because of this, the diode conduction time of the bridge style rectifier decreases and the conduction direct current peak value increases and in addition the waveform of the increased input electric current is distorted. Therefore this low power factor class of equipment and products, besides wasting energy, also increases the unnecessary virtual work for power companies.
From this it can be seen that the above mentioned conventional product has many drawbacks, and is not an ideal design, and urgently needs improvement.
Aimed at the flaws and drawbacks of the abovementioned AC/DC converter, this inventor was eager to improve and innovate, and after years of concentration and painstaking research, has finally successfully developed this kind of non-isolated AC/DC converter having power factor correction.